Abstract:The influence of ambient temperatures on charging capacities of 18650 type LFP and NCA batteries were investigated in this paper, and the performance in low temperature was compared. Electrochemical impedance measurements were taken in various temperatures, the values of ohm, film and charge transfer resistances were confirmed according to equivalent circuits. As for LFP batteries, ohmic resistance and film resistance are well meet the Arrhenius relations in the range of -10~25 ℃, however, in a wider range of -10~50 ℃ charge transfer resistance is well meet. However, as for NCA batteries, film resistance and charge transfer resistance are complyed with Arrhenius relations in range of 0~50 ℃. The comparison analyses of solid phase ion diffusion coefficient in different temperatures indicate that the ion diffusion rate of LFP battery is obviously affected by low temperatures, nevertheless, slightly affected for the NCA battery.